JPS6152405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to chemical laboratory operations in storing, transporting and/or dispensing reagents from manufacturers to end users in the laboratory, and also relates to the use of specific, digitally programmed sample It also relates to chemical laboratory work with reagents in the laboratory in accurately transferring amounts of and likewise in delivering specific, digitally programmed amounts of reagents.

The present invention provides a novel, low cost, disposable reagent container and a pipette diluter that allows the container to be used without valves or interconnected tubing.
A novel digitally controlled actuating mechanism that acts on a container to act as an actuator.

The present invention solves the problem of sample and reagent volume determination by digital programming and signal processing techniques.

Today, reagents are usually delivered to laboratories in conventional bottles. Measure the amount delivered from these bottles. There is a whole range of volumetric devices available on the market, from simple manual types that draw a volume of liquid into a graduated tube or cavity (pipette) and squirt it back out as a measured volume; There are even fully automatic devices that draw the reagent from a reagent bottle or container into a syringe and expel it again in a measured amount determined by the stroke and diameter of the syringe's plunger.

The pipette diluter involves two different volumes, one specific volume of sample being sucked into the probe tip and later flushed out along with a second specific volume of reagent. Today, such devices have two syringes or pumps, one for the sample and one for the reagent.
Pumps and reagent containers are interconnected by tubing and valves.

The disadvantages of these devices are that the valves are expensive to design and manufacture, and that the valves are often a source of trouble and malfunction. Furthermore, if it is desired to change reagents in this device, the valves and interconnecting tubes must be filled with new reagent, rinsed off, and replaced with new reagent. This results in wasted reagents, apart from being time consuming and cumbersome to operate.

The present invention overcomes the aforementioned disadvantages by making the reagent storage, sample syringe, and reagent syringe one single unit, avoiding the need to interconnect all transfer and tubing and valves. It is something to be overcome.

In the past, it was virtually impossible to remove or deliver a very small amount of sample, for example 100,000, from the total volume of the syringe. The reason for this is that the plunger within the syringe was moved by mechanical means and by a mechanical stop to determine the amount taken or delivered. The problem is that the plunger in the syringe has a seal that causes friction and stiction against the wall of the syringe.

This must be overcome before the plunger can move. To overcome sticking, a certain force must be applied. This force slightly distorts the mechanical linkages and stops designed to move the plunger a given distance. When the plunger is released from the stick, the force to overcome the stick is also released and the plunger suddenly springs up, changing the amount of reagent delivered by that amount. This quantity is very difficult to measure and control, and it sets a limit on the minimum quantity that can be reliably handled.

The present invention overcomes this problem by applying a force to the plunger and seal that, when released from sticking, does not move the plunger directly in the delivery direction. The plunger is released by rotational movement. Although such a movement is substantially neutral with respect to the delivery direction, it nevertheless has the effect of freeing the plunger from sticking.

Another disadvantage of prior art devices is that the forces that move the plunger in the delivery direction are applied to the plunger through relatively large and complex mechanical structures (several inches in size), thus reducing elasticity and tolerances in the device. is added to the error in the controlled variable, which sets a limit on the minimum amount that can be handled accurately and reliably.

The present invention overcomes these difficulties by applying the force to move the plunger directly between the plunger and the wall of the syringe. A plunger acts as a micrometer screw within the syringe base. There is no distance between the plunger and the advancement mechanism. This is because the plunger advances itself against the syringe wall it is in contact with.

A disadvantage of prior art devices is that they are expensive. The expense is due to the high degree of mechanical precision required in the syringe and valve system, and the complexity of mechanical programming and volume control.

There is great potential for cost savings when going from mechanical precision and programming to electronic precision and programming.

The present invention achieves this cost reduction with a low cost disposable syringe that does not require complex valves or tubing, and with an electronic digital control program. In its simplest form,
This control is accomplished by a preset counter.

Taken together, the main object of the present invention is to avoid the sudden spring-up of the plunger that occurs when the plunger is released from the adhesion of the sealing body when it starts moving, and to minimize the error in the controlled variable in the direction of delivery of the plunger. It is an object of the present invention to provide a dispensing device configured to.

To achieve the above object, according to the invention, the plunger is provided with a circumferential thread having a cutting edge that cuts a corresponding slit in the inner surface of the container simultaneously with the relative rotation of the plunger and the container, and the sealing member is attached to the plunger. disposed between the plunger and a flow path that is fixed to and slidable relative to the inner surface of the cylindrical container and communicates with the interior of the container, and further provides a range of relative rotation between the plunger and the container. All you have to do is arrange a means to do so.

Hereinafter, the present invention will be explained with reference to the accompanying drawings.

The container shown in FIG. 1 is constructed with a main body preferably made of a relatively soft but resilient plastic material. Standard disposable syringe bodies of the type readily available on the market are suitable. Disposed within this body is a plunger 2, preferably molded from a hard resilient plastic of the polyamide type, such as Durothan. The plunger is provided with a sealing member 3 made of silicone rubber or other soft flexible material. This sealing member may be of the type used in readily available disposable syringes. The plunger has a threaded part 4 with a thin threaded rim. This threaded section 4 is slightly larger than the base of the syringe tube and is divided into several sectors 5. Each sector acts as a spring pressing against the thread, so that the thread penetrates the wall 6 of the syringe and cuts a groove in the wall. This spring action can be increased by metallic steel springs (not shown) acting on each sector. This is of value if the plunger is made of a material that flows easily and therefore loses its elasticity while being subjected to strain over long periods of time.

The threaded portion 4 of the plunger is connected to the inner wall 6 of the injection container body.
Acts as a micrometer screw. The wall of the syringe may be pre-threaded. This is because the soft seal 3 fills the thread in the wall of the syringe, and since both plunger and seal rotate together, the plunger and seal move together axially as they rotate. The spring action of the plunger sector eliminates the need for bumps or play between the plunger and the syringe wall.

However, it is desirable that the walls of the syringe be smooth and not threaded. In this case, the plunger acts as a kill pin screw on the base of the syringe. A specially shaped thread for the plunger is advantageous. FIG. 2 shows a schematic diagram of this thread hoop. This thread has tall sharp ridges. The purpose of this knife-like ridge is to cut a groove in the wall of the syringe by deforming the wall material without removing it. In practice, a very shallow thread is sufficient. This is because the rotating seal is free of stickiness and there is less friction during movement of the seal, so the force required to advance the plunger is relatively small. A recess 7 is arranged in the wall 6 of the syringe, the purpose of which is to prevent the plunger from unintentionally slipping out of the syringe. A flange 8 is provided on the outside of this recess.

An irregularly shaped recess (not shown) is provided in the center of the flange, the purpose of which is to engage the rotary drive shaft. The shape of this recess is appropriately triangular.

As shown in FIG. 3, the plunger 2 is connected to a rod 9 which cooperates with the triangular recess mentioned above.
At the opposite end of the rod 9 there is a support plate 1 arranged vertically.
0 is provided, and this support plate supports pins 3 and 14.
It carries two ball bearings 11, 12 mounted on the. The outer rings of ball bearings 11, 12 are adapted to move within tube 15 and in relation to diametrically opposed tube corners 16, 17, as seen in FIG. Ball bearings 11, 12 are under pressure in tube 15. To apply this pressure, increase the distance between the centers of the ball bearings a little to get a better fit. Although the tube 15 is rotatable, the reason for loading the ball bearings is to minimize play or angular backlash so that when the tube 15 is rotating, the rod 9 follows this rotation as closely as possible. It's for a reason. A rod 9 passes through a hole in the end plate 18 of the tube 15, and at the opposite end of the tube 15 a flexible disk 19 is provided.
is provided. This flexible plate 19 has a shaft 22
The shaft 22 carries a disk 23, which in turn carries a pusher 20 which can be connected to the pusher 20. Its functions will be described later. The shaft 22 belongs to a reduction gear 24 , which in turn is connected to a motor 25 . A weak spring 26 is provided between the flexible disk 19 and the ball bearing end of the rod 9, which keeps the outer end of the rod 9 engaged with the plunger 2. The purpose of the flexible disk is to allow some movement of the tube 15 and rod 9. In this way, the disk is very rigid against the threads, thereby minimizing the requirements for close tolerances during manufacturing without compromising performance. As can be seen in FIG. 3, the rod 9 and associated details can be moved in the direction of the two arrows 27.

A motor 25 is supported by the bottom 28 of the housing 29. The upper flat end 30 of the housing 29 carries a sleeve 31 with an internal thread 32, which is connected to an external thread 33 of a nut 34 adapted to press against the flange 8 of the container body 1 containing the plunger 2. Collaborate with The disk 23, on which the flange 8 abuts the surface of the end 30, is an optical encoder disk having, for example, 1000 opaque and translucent spots around its periphery. Said disk 23 cooperates with a light source 35 arranged on a support member 36, which also carries a lens 37 and a photovoltaic cell 38. When light source 35 illuminates disc 23, it produces an image on photocell 38. The photocell senses dark or bright spots on the disc 23 depending on the rotational position of the disc. One full revolution of the disk provides 1000 pulses of light to the photocell 38 in this example.

In FIG. 5, the apparatus shown in FIG. 3 is shown together with the associated electrical circuitry. These electrical circuits are in the form of simple digital programmable mechanisms. The circuit described above is simple but sufficient to operate the container and actuator as a digitally programmed pipette router. The electric motor 25 is a reversible AC motor equipped with three connecting wires 39, 40, and 41. An electric wire 39 is connected to the main power source via a relay contact 42. Electric wire 40
A capacitor 4 is connected between and 41 to obtain a pseudo phase.
3 is connected. Electric wire 40 is one contact 44
The electric wire 41 is connected to the second contact 45 of the switch 46, and the switch 46 is then connected to the other terminal of the main current. In this way,
The direction of rotation of the motor depends on which contact the switch 46 is connected to. In the illustrated neutral position, the motor is disconnected.

A photovoltaic cell 38 is connected to the input of a binary counter 47. The counter may be of a type easily available on the market. This counter has a series of binary outputs, any of which can be connected at once to either contact 48, 49 of a switch 50 forming part of switch 46. A switch 50 is connected to the base 52 of a transistor 53 by a resistor 51. The emitter of the transistor is connected to voltage source B, and its collector 55 is grounded via a relay coil 56, which actuates the aforementioned relay contact 42. Counter 47 has a reset terminal 57 connected to voltage source B through resistor 58. Said terminal 57 is connected to both contacts 59 and 60 of a switch 61, which, like switch 50, is part of switch 46. Switch 61 is grounded and connected to voltage source B as shown in FIG.

The container 1 is connected by a hose 62 to a delivery tip 63 for transfer into a container 64 containing a sample liquid 65. The above-mentioned delivery tip piece 6
3 can also be moved into another container 66 as shown in dotted lines. This latter container 66 is a receiver into which the metered sample from container 64 is delivered together with the metered amount of reagent from container 1. The feeding tip piece 63 may be constructed of a feeding tip piece of an easily available type.

The operation of the apparatus of FIG. 5 is as follows.

Assume that switch 46 and associated switches 50 and 61 are in the neutral position. The desired sample amount is selected by connecting the appropriate output from counter 47 to switch 48, a so-called sample position contact. The desired dilution amount is selected by connecting the appropriate output of counter 47 to contact 49, which is the dilution contact of switch 50. The delivery tip piece 63 is placed in the sample container 64 and moved into the sample liquid 65. Move the lever of switch 50 to contact 48, which is the sample position contact. At the same time, contact 4
6 and 61 are moved to contacts 45 and 59, respectively. This prepares the counter 47 to receive a pulse from the photocell 38 and the motor begins to rotate, unscrewing the plunger 2 from the container 1 and thus removing the sample from the test liquid container 64. at the same time,
The photocell records the number of lines on the disk 23 that it passes, and a counter 47 counts these lines. Contact 4
When the output terminal of the counter 47 connected to 8 becomes high, the transistor 53 is momentarily cut off, ie there is no current available in the relay coil 56, so that the relay contact 42 is opened and the motor is stopped.

Now, the delivery tip 63 is placed in the reagent container 66 and the switch 50 is moved to the delivery position, ie, brought into contact with the contact 49. This moves switches 46 and 61 to their respective contacts 44 and 60. When moving to the delivery position, the counter 47 is reset by passing through the neutral position. This is because switch 61 opens the connection between terminal 57 and ground. Now, the electric motor starts rotating in the opposite direction and screws the plunger 2 into the container 1, thus delivering a specific amount. Pumping continues until counter 47 registers a sufficient total to cause the output connected to contact 49 to go high. At this moment, the transistor 53 is cut off again, the relay contact drops, and the motor 25 stops again.

Above is the complete sample and dilution program cycle. The entire device is very precise and starting friction forces can be virtually eliminated by the arrangement of the plunger which screws itself into and out of the container. Even if there is a large frictional force when the tube 15, rod 9 and plunger 2 begin to rotate, the axial movement of the plunger associated with such an unavoidable friction jump-up is of no practical importance. . The shape of the thread 4 of the plunger 2 can be varied within the scope of the invention, and the inner wall 6 of the container can also be pre-threaded as described above. Preferably, the container 1 is made of a somewhat resilient material, such as styrene plastic, which is a material that is easy to thread. In order to obtain a seal between the wall 6 of the container and the thread 4 of the plunger, a thread with a non-linear slope can be provided. The rotation mechanism of the plunger may be varied within the scope of the invention, although the illustrated mechanism is a good practical solution.

The quantity control circuitry may be varied to include other types of preset counters and other types of motors, such as step motors, for operation, all within the scope of the invention.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the reagent container, Fig. 2 is a sectional view of a detail of Fig. 1, Fig. 3 is a partial sectional view of the reagent container arranged in the delivery mechanism, and Fig. 4 is a line taken along the line of Fig. 3. 5 is a schematic diagram of the reagent container and delivery mechanism connected to a digital programmer and assembled for a transfer dilution operation. 1... Container, 2... Plunger member, 4... Threaded part,
9... Rod, 11, 12... Ball bearing, 15... Pipe, 23...
Disk, 24... Reduction device, 25... Motor, 35... Light source, 36... Support member, 36... Photovoltaic cell, 47... Counter, 62, 63... Tube means.

Claims (1)

[Claims] 1. A container 1 having a cylindrical inner surface 6, and this container 1
a plunger 2 having a flow path communicating with the inside of the container 1, an annular sealing member 3 disposed within the cylindrical container and sealing between the plunger 3 and the inner surface of the container 1; and means for axially displacing the plunger relative to the container while displacing the plunger along the container, the plunger 2 having a relative rotation between the plunger and the container. a circumferential thread having a cutting edge which simultaneously cuts a corresponding slit in the inner surface 6 of the container 1 upon rotation, said sealing member 3 being fixed relative to the plunger;
Means is arranged to be slidable relative to an inner surface of the cylindrical container and located between the plunger and the flow path for providing a range of relative rotation between the plunger and the container. A dispensing device characterized by: 2. The circumferential thread consists of several threads arranged at a distance from the annular sealing member 3, said distance corresponding at least to the axial distance between said threads. A dispensing device according to claim 1. 3. Said means for effecting a relative rotation between the plunger and the container comprise a disk 23 carried by the output shaft of a motor 25 and provided with a transparent part, which rotates the rod 9 in question. 3. A dispensing device according to claim 1 or 2, adapted to cooperate with a detection device 38 for detecting the number of transparent parts passed when the dispensing device is moved. 4. Dispensing device according to claim 3, wherein the detection device is constituted by a photovoltaic system 38 connected to a counting circuit 47 for counting the number of transparent parts. 5. According to claim 4, the counting circuit 47 is presettable and connected to the operating circuit of the motor for stopping the motor when said preset condition is fulfilled. distribution equipment. 6 A container 1 having a cylindrical inner surface 6, a flow path communicating with the inside of the container, and an annular sealing member 3 disposed within the cylindrical container and sealing between the plunger 3 and the inner surface of the container 1. and means for axially displacing the plunger relative to the container while displacing fluid along the flow path and at the same time providing relative rotation. The plunger 2 is provided with a circumferential thread having a cutting edge that cuts a corresponding slit in the inner surface 6 of the container 1 at the same time as the plunger and the container rotate relative to each other, and the sealing member 3 is fixed to the plunger. and is slidable relative to the inner surface of the cylindrical container,
and disposed between the plunger and the flow path,
Means for effecting a range of relative rotation between the plunger and the container are arranged, the means for effecting a range of relative rotation between the plunger and the container carried by the output shaft of the motor 25 and a transparent In the dispensing device, it has a disk 23 with sections, which disk is adapted to cooperate with a detection device 38 for detecting the number of transparent sections passed when the rod 9 in question is rotated. , a passage member is arranged between the output shaft 22 of the motor and the plunger, said passage member being constituted by a rod 9 connected to the plunger at one end and having a rectangular cross section at the opposite end. Low-friction sliding means 11, 12 are provided for sliding in the axial direction within the tube, and the low-friction sliding means are suitably constituted by two ball bearings pressed against opposite corners of the rectangular tube, and the tube is A distribution device characterized in that the distribution device is connected to the output shaft 22 of the motor 25. 7. The connection between the rectangular tube 15 and the motor 25 is constituted by a flexible disk member 19 placed at one end of the tube, and the central portion of the disk is connected to the output shaft 22 of the motor by a bushing 20. , a dispensing device according to claim 6. 8 Said disk 19 is connected to said opposite end of rod 9 by a spring 26, thereby forcing said rod 9 into engagement with said plunger and said container 1
8. A dispensing device according to claim 7, wherein the dispensing device is mechanically coupled to the motor 25.